Electromagnetic properties of dark matter: dipole moments and charge form factor

TL;DR

This paper explores electromagnetic interactions of neutral dark matter particles with nuclei, calculating scattering cross sections and spectra, and shows how certain dark matter models can explain experimental excesses.

Contribution

It provides complete formulas for scattering and recoil spectra for dark matter with dipole moments and charge form factors, linking theory to direct detection experiments.

Findings

7 GeV dark matter with EDM, MDM, or CFF can explain CoGeNT excess

Calculations include cross sections and recoil spectra for electromagnetic interactions

Models remain consistent with null search constraints

Abstract

A neutral dark matter particle may possess an electric dipole moment (EDM) or a magnetic dipole moment (MDM), so that its scattering with nuclei is governed by electromagnetic interactions. If the moments are associated with relevant operators of dimension-5, they may be detectable in direct search experiments. We calculate complete expressions of the scattering cross sections and the recoil energy spectra for dark matter with these attributes. We also provide useful formulae pertinent to dark matter that interacts via an electric charge form factor (CFF) which is related to the charge radius defined by an effective dimension-6 operator. We show that a 7 GeV dark matter particle with an EDM, MDM or CFF easily reproduces the CoGeNT excess while remaining consistent with null searches.